title: Evolution of the haemagglutinin gene of the influenza A(H1N1)2009 virus isolated in Hong Kong, 2009-2011.
abstract: Phylogenetic analysis of the haemagglutinin (HA) gene shows that the influenza A(H1N1)2009 viruses collected in Hong Kong clustered in two main branches characterised by the E391E and E391K amino acids. The main branch E391K evolved in two sub-branches with N142D and S202T mutations that first appeared in March and July 2010, respectively, with the latter becoming the predominant strain. These genetic variants that emerged display similar antigenic characteristics.Concurrent with genetic surveillance, laboratories should continue monitoring the circulating viruses antigenically.
authors.affiliation: Virology Division, Public Health Laboratory Services Branch, Centre for Health Protection, Department of Health, Kowloon, Hong Kong.
authors.forename: G C
authors.initials: GC
authors.lastname: Mak
authors.forename: C K
authors.initials: CK
authors.lastname: Leung
authors.forename: K C
authors.initials: KC
authors.lastname: Cheng
authors.forename: K Y
authors.initials: KY
authors.lastname: Wong
authors.forename: W
authors.initials: W
authors.lastname: Lim
mesh_terms: D000914:Antibodies, Viral / Q000235:genetics; D005075:Biological Evolution; D019143:Evolution, Molecular; D005814:Genes, Viral; D014644:Genetic Variation; D019267:Hemagglutinin Glycoproteins, Influenza Virus / Q000032:analysis / Q000235:genetics* / Q000276:immunology; D006723:Hong Kong; D006801:Humans; D053118:Influenza A Virus, H1N1 Subtype / Q000235:genetics* / Q000276:immunology / Q000302:isolation & purification; D007252:Influenza Vaccines / Q000235:genetics; D007251:Influenza, Human / Q000453:epidemiology / Q000235:genetics* / Q000276:immunology; D009154:Mutation; D009439:Neuraminidase / Q000032:analysis / Q000235:genetics; D010802:Phylogeny; D012367:RNA, Viral / Q000235:genetics; D017422:Sequence Analysis, DNA
chemical_list: D000914:Antibodies, Viral; D019267:Hemagglutinin Glycoproteins, Influenza Virus; D007252:Influenza Vaccines; D012367:RNA, Viral; C483468:hemagglutinin, human influenza A virus; D009439:Neuraminidase